Rotary plow feeders of various designs have been in use for many years. In general such feeders include a bin, hopper or other container for granular material having a bottom wall provided with a central feed aperture and a rotary plow device located above the feed aperture and close to the bottom wall. Rotation of the plow device about the vertical axis of the feed aperture results in engagement of the granular material with the plow device which is shaped to urge the granular material by a scooping action toward the feed aperture. The material is thus pushed over the edge of the feed aperture to fall by gravity from the container.
A search conducted with respect to the present development identified U.S. Pat. Nos. 217,628, 243,716, 371,881, 1,856,361, 3,036,745 and 4,020,980, of which the first three were considered to be more relevant than the others.